1. Field of Invention
This invention relates to clamps particularly hose clamps that are used to constrict hoses on fittings or other objects to be confined.
2. Prior Art
It is common practice to fasten a tube or hose to an end fitting or connector so the contents of the tube or hose may reach its destination or the final connection. The hose or tube must be securely attached to the fitting usually this is accomplished by compressing the tube or hose around the circumference of the fitting. These devices are known generally as hose clamps.
The present invention relates generally to hose clamping devices and particularly an improved hose clamp apparatus. Other general uses of this invention may apply to similar devices that are used to constrict items such as wires, a collection of small tubing or other items or objects needing confinement. Since the beginning use of hoses, hose clamps, a necessary apparatus, have come in a large variety of designs. None of which have completely satisfied the use advantages but have unfortunately incorporated many disadvantages in there overall design. Some of the problems have been addressed but not adequately and never completely in one clamp.
A frequent problem is hose clamps and hoses are positioned in confined spaces or visually out of sight so that only one hand may be used when, tightening or loosening a clamp. The preferred clamp used today is referred to as the “worm screw” type such as patented by Hill et al., U.S. Pat. No. 2,395,273 (1946), Black, U.S. Pat. No. 2,944,314 (1960), Rueckheim U.S. Pat. No. 3,371,392 (1966), E. E. Schaefer U.S. Pat. No. 2,767,455 (1956) H. P. McKown, Jr. U.S. Pat. No. 3,195,204 (1965), C. E. Hathorn U.S. Pat. No. 2,268,211 (1941), E. W. North et al U.S. Pat. No. 2,386,629 (1945), C. W. Tinsley U.S. Pat. No. 3,087,220 Patent (1963), Allert U.S. Pat. No. 4,445,254 (1984) and L. Baldo U.S. Pat. No. 2,522,494 (1950) these types of hose clamps are accessible primarily from an adjacent direction substantially tangential to the hose, when using a tool to tighten or loosen the clamp it is virtually impossible without the use of another hand to hold the clamp in place since they tend to rotate around the circumference of the hose, when loose. Unfortunately tight areas and hard to reach places are common when using hoses and fittings. This invention solves this critical problem and others as described below.
Other types of hose clamps have tried to address this critical problem but not in a complete manner such as Kreft, U.S. Pat. No. 4,546,524 (1985) with a metal “worm gear” type hose clamp. Kreft has positioned a tightening wrench opposed to the axial of the hose, however it appears that the hexagonal wrench can only be inserted on one side of the head limiting its practical use in hard to reach spaces. Also, the patent does not describe in detail the means of attachment of the locking and gear section to the band or strap, which is critical to its function and cost of manufacture. The strength of the teeth is also a factor due to their nominal width as well as the depth of engagement in the slots in the strap are also questionable. Difficulty appears when the engaging member tab, holding the gear in a stop position where as the hexagonal wrench must be withdrawn so the gear will slide into position by means of a spring. If the hexagonal wrench is removed, force cannot be maintained against the spring causing counter rotation of the gear releasing the strap. Small thin metal tabs are all that prevents the clamp from disengaging as well as a fine steel spring to engage the stop incidence of corrosion are common and will certainly cause this clamp to fail.
Younce, U.S. Pat. No. 1,874,731 (1932) also addresses longitudinal axis but is specifically designed as a “piston ring compressing tool” not a hose clamp. Kitts, U.S. Pat. No. 2,383,199 (1945) and Brodheim, U.S. Pat. No. 2,641,817 (1953) not in general use today for other apparent reasons as described below, they do employ a screw head oriented substantially parallel to the central longitudinal axis of the circular band for tightening. Brodheim, U.S. Pat. No. 2,641,817 (1953), Kitts U.S. Pat. No. 2,383,199 (1945) and W. C. Dumke U.S. Pat. No. 1,963,436 (1934) employ a separate paw and ratchet on an eccentric wedging member to lock the clamp apparatus also employed are metal straps or a flexible band around a winding element. All of which have exposed mechanisms that can become entangled with adjacent apparatus or cause injury by having exposed sharp edges. It also appears some difficulty would be encountered releasing the ratchets when under reverse force from the tightened strap. Kitts U.S. Pat. No. 2,383,199 (1945) as mentioned above this device may also be accidentally released by the exposed position of the ratchet paw. Another major flaw in all the above clamps is that the parts are all various types of metal costly to fabricate, manufacture and assemble. In a relatively short time, under certain conditions, all metal even high quality will corrode, fatigue and erode, especially made from thin sheet metal with no substantial thickness.
Many of these perforated strap clamps are used on soft flexible hose materials so as the band is tightened the soft hose material is pushed through the perforations in the band damaging the hose and with some designs pushing the “worm gear” away from the perforations in the strap ultimately disengaging the clamp. It has been demonstrated that “worm gear” design when over tightened will fracture or bend the metal between each perforation of the strap since they are close together with little metal support between each perforation. Little surface contact between the “worm gear” and the perforations also causes failure.
Another desirable feature of a hose clamp is to provide a quick or rapid disconnect. Toth, U.S. Pat. No. 5,063,642 (1991) attempts to address rapid disengagement of a “worm gear” type clamp. Although it appears that in order to release the gear from the slotted strap it would have to be pried up with a tool not easily accomplished in tight surroundings or areas out of sight. In addition all the clamps cited above are fabricated from metal, costly to fabricate, manufacture and assemble.
Other references cited are clamps primarily made of polymeric material such as LiVolsi, U.S. Pat. No. 4,483,556 (1984) this hose clamp which is injection molded is less expensive to produce and uncomplicated to manufacture. Made from polymeric material it will not corrode or degrade as metal clamps. Although it has no means to disengage and is designed to be finger tightened only limiting its use. Today most hose clamps used for low pressure applications are “worm gear” types. All hose clamps of this type as described above in various forms suffer from a number of disadvantages:                (a) Hose clamps based on the “worm gear” design principle cannot be applied or removed using only one hand. A distinct disadvantage in many applications.        (b) All prior art hose clamps designed for medium pressure applications are fabricated from metal. Under certain adverse conditions such as exposure to acids, salts, electrolysis, flexing, vibrations and the like may degrade these clamps to the point of failure, even high quality stainless steel.        (c) The majority of hose clamps used today do not embody means to rapidly and easily disengage.        (d) The need to use tools to install or remove hose clamps such as slotted screwdrivers or ratchets in places inaccessible or completely out of view is cumbersome a distinct disadvantage.        (e) Another disadvantage is the inability to color code in order to identify the contents being carried within a hose and could be a safety issue.        (f) To assembly metal hose clamps you must consider the cost of material, overall energy necessary to manufacture and form parts, labor and assembly equipment, manufacturing space, shipping, as well as other peripheral expenses. These costs are exceedingly greater than a polymeric composite, injection molded, hose clamp.        (g) Some hazards of using metal hose clamps are injuries and cuts from sharp edges and accidental electrical conductivity.        